The methodology of sample design which is applied to estimating change in land use and land cover is general and extendable to determination of change in any type of thematic mapping that is time variant. Land-use maps of the State of Pennsylvania at a scale of 1:250,000 were compiled circa 1958 with land use classified into six categories. The more detailed land-use and land-cover mapping of the State of Pennsylvania at a scale of 1:250,000 was completed by the U.S. Geological Survey circa 1977. With some rearrangement of these categories, the recent maps are very nearly compatible with a combination of five categories of the earlier maps. -from Author